Hi Timothy thanks for the information.

I have the A190's midi thru jack wired internally to the
A191's midi in jack with two short lengths of wire. That's been
working fine for a couple of years.

So now I'm thinking that if I connect a cable from a rear-panel DIN
socket to the terminals on the A190's midi in jack, whatever opti-iso
stuff is going on should be preserved. Do you think

Joe

--- In Doepfer_a100@yahoogroups.com , "Tim Stinchcombe" <timothy@t...>
wrote:

> Hi Joe,
>
> > Speaking of connectors in the back, if I were to install a DIN
> socket
> > in back of an A100 frame and wire the midi signal internally to

the

> > A190 and A191, would simple wire work OK Shielded two-conductor
> Thin
> > coax
>
> The simple introductory book I have on MIDI says that screened twin
> core cable of audio quality is fine. BUT, MIDI is not
> straightforward. It works off a 'current loop', with opto-isolators
> used to ensure that interconnected bits of kit are electrically
> isolated from one another. The book strongly advises against trying
> to drive two inputs from a single output (you wouldn't be able to
> guarantee that either input would work properly) - this means that
> you would still have to run your A-191 from the 'thru' of the A-190
> (although conceivably you could connect them internally). Also the
> point of using screened cable is to prevent interference
> from 'escaping' from the lead, and not from noise penetrating it -
> the screen on a lead is attached to both pin 2's at either end, but
> the pin 2 on any socket is *not* connected to the chassis, in order
> to maintain the isolation of all bits of kit.
>
> I'm not sure how helpful the above is - you were obviously expecting

> to connect things internally, only it might be less simple than you
> had imagined ( ).
>
> Tim